Wisconsin's Feingold avoiding Democratic presidential pick

The question is much more than a ballot choice for Democrat Russ Feingold, whose hopes of reclaiming the Senate seat he held for 18 years rests with Wisconsin voters heavily invested in the presidential nomination fight.

Feingold wants to avoid alienating Democrats, especially young voters, and keep them united behind his quest to win his way back to the Senate.

Johnson also has not endorsed anyone in the muddled Republican presidential race, dodging the endorsement question despite being repeatedly asked to take a stand on sometimes inflammatory comments made by Donald Trump.

Feingold, in a statement to The Associated Press, praised the Democratic candidates for having a "healthy, substantive debate about the issues that matter most to middle class and working families," while saying Republican presidential hopefuls are trying to "demonize and alienate as many Americans as possible."

Feingold has focused much of his campaign on wooing those younger voters, visiting college campuses and emphasizing his plan to lower the student financial debt burden.

Betsy Ankney, Johnson's campaign manager, said Feingold "faces the lose-lose proposition of running with a fellow professional politician nobody trusts, or a self-admitted Socialist who shares his far-left ideology."

Clinton has strong support among Wisconsin Democratic Party insiders, known as superdelegates, who will cast ballots for a presidential nominee at the national convention.